package Z3;

import java.util.*;

public class Test {
	public static void main(String[] args) {
		Hashtable<Integer, String> ht = new Hashtable<Integer, String>();
		Map<Integer, String> map = new HashMap<Integer, String>();
		//ht.put(null, null);
		map.put(null, null);
		map.put(1, "Ala");
		map.put(2, "i");
		map.put(3, "Ola");
		System.out.println(map);
		Map mapSynchro = Collections.synchronizedMap(map);
		Map mapNiemod = Collections.unmodifiableMap(map);
		map.put(4, " i kot");
		System.out.println(map);
		System.out.println(mapNiemod);
		//mapNiemod.put(4, " i kot");
		
		Set<String> set = new HashSet<String>();
		set.add("Ala");
		set.add("i");
		set.add("Ola");
		Set setNiemod = Collections.unmodifiableSet(set);
		System.out.println(setNiemod);
		//setNiemod.add("i kot");
		
		
		

	}

}
